Tessa Wong

BBC News, Asia Digital Reporter

Reporting fromTaipei

Taipei is due to come to a standstill as the capital of Taiwan holds one of its largest-ever civil defence exercises against a possible Chinese invasion.

Air raid sirens will ring out across the metropolitan area on Thursday, and in some areas residents must seek shelter indoors, while traffic will grind to a halt. The city will also hold mass evacuation drills and mass casualty event rehearsals.

The exercise is held in conjunction with Taiwan’s largest ever war games – the annual Han Kuang exercises – as the island increasingly ramps up its defences.

China claims self-ruled Taiwan as its part of its territory and has not ruled out the use of force to “reunify” with the island.

Tensions have increased since last year when Taiwan elected its president William Lai, whom China reviles as a “separatist”.

While previous Han Kuang exercises also had civil defence components, this year authorities have combined them in a single Urban Resilience exercise across the island which began on Tuesday and ends on Friday.

Each day of the exercise sees air raid sirens ringing out for half an hour in several cities across Taiwan.

Residents in designated areas in each city must shelter indoors – or risk incurring a fine – and all shops and restaurants must pause operations. Road traffic must also come to a stop, with drivers required to pull over and head indoors immediately.

In Taipei, emergency workers and volunteers will take part in evacuations of a market and temple, schools, subway stations and highways.

They will also hold a mock mass casualty event and practise their response in treating the injured, and set up distribution points for emergency supplies.

This week’s Urban Resilience exercise is the latest civil defence drill Taiwan has held this year as it tries to prepare its cities for possible attacks and raise its population’s defence awareness.

While US officials have warned of an imminent threat from China and that President Xi Jinping wants his military to be capable of invading Taiwan by 2027, most Taiwanese remain sceptical that an actual invasion will take place.

One poll done last October by a government-linked think tank, the Institute for National Defence and Security Research (INDSR), found that more than 60% of Taiwanese do not believe China will invade in the next five years.

“The chances of China invading are low. If they really wanted to invade us, they would have done it long ago,” said Ben, a 29-year-old finance professional interviewed by the BBC in Taipei on Wednesday.

“But I do believe we need these drills, every country needs it and you need to practise your defence… I believe there is still a threat from China.”

But a few were sceptical.

“There is just too big a difference in the strengths of China and Taiwan’s militaries,” said Mr Xue, a 48-year-old office worker. “There is no use defending ourselves against an attack.”

The IDSR poll had found that only half of Taiwan’s population had confidence in their armed forces’ capability to defend the island.

It is a long-running sentiment that has spurred the Taiwanese government in recent years to beef up its military and expand Han Kuang.

More than 22,000 soldiers – about 50% more than last year – rehearsed defending the island from potential attacks from China in land, sea and air drills.

Newly acquired military hardware such as the US-supplied Himars mobile missile system as well as Taiwan-made rockets were tested.

This year’s Han Kuang exercise also focused on combating greyzone warfare and misinformation from China, as well as rehearsing military defence in cities.

In recent days soldiers took part in urban warfare exercises in an exhibition centre and on the subway in Taipei.

On Wednesday the military rehearsed pushing back enemy troops on the streets of Taichung city, and turned a high school in Taoyuan into a battle tank repair station.